import math
L=list(map(float,input().split()))
A=(L[0]-L[2])*(L[0]-L[2])
B=(L[1]-L[3])*(L[1]-L[3])
V=math.sqrt(A+B)
print(round(V,8)) import math math L=list(map(float,input().split())) L list(map(float,input().split())) list map(float,input().split()) map float input().split() ().split () input split A=(L[0]-L[2])*(L[0]-L[2]) A (L[0]-L[2])*(L[0]-L[2]) L[0]-L[2] L[0] L 0 L[2] L 2 L[0]-L[2] L[0] L 0 L[2] L 2 B=(L[1]-L[3])*(L[1]-L[3]) B (L[1]-L[3])*(L[1]-L[3]) L[1]-L[3] L[1] L 1 L[3] L 3 L[1]-L[3] L[1] L 1 L[3] L 3 V=math.sqrt(A+B) V math.sqrt(A+B) math.sqrt math sqrt A+B A B print(round(V,8)) print round(V,8) round V 8 B=(L[1]-L[3])*(L[1]-L[3]) (L[1]-L[3])*(L[1]-L[3]) B A=(L[0]-L[2])*(L[0]-L[2]) (L[0]-L[2])*(L[0]-L[2]) A V=math.sqrt(A+B) math.sqrt(A+B) V L=list(map(float,input().split())) list(map(float,input().split())) L
import math
L=list(map(float,input().split()))
A=(L[0]-L[2])*(L[0]-L[2])
B=(L[1]-L[3])*(L[1]-L[3])
V=math.sqrt(A+B)
print(round(V,8))
